1. Field of the Invention:
This invention relates to a squeezable self closing plastic valve which relies upon novel structural features to assist the inherent memory of the plastic material, to perform and retain its ability, to flex and seal. The valve can be made, as a separate unit for fastening to a container or, by clamping, heating, compressing and cooling the neck of a thermoplastic bottle or container, immediately after the product filling operation. During the heat forming of the valve, the discharge lips can be sealed gas tight, with a tear-off type shipping tab, which offers tamper protection during storage until torn off by the consumer. After the removal of the seal tab, a compression type lip seal clip may be used, for compressing the valve discharge lips tighter than normal, for prevention of decarbonation of the likes of soft drinks, or leakage that could occur should the container be jostled or manhandled. Normally, for readily consumable products, such as milk and juices or high viscosity pastes, the lip seal clip is not required. An alternate method for filling the container with product, can be accomplished by pre-molding the flexible thermoplastic self-closing valve portion with its separable shipping lip seal tab portion unsealed as integral parts of the container. After the product filling of the container, accomplished by squeezing the self-closing valve portion in the open position, the shipping lip seal tab can be heat sealed closed.
The self closing valve can be applied to all types of plastic containers such as squeezable, collapsible tube type, bellows and even rigid plastic, metal or glass containers.
This invention also relates to the bottle closure industry. It offers a new, simpler and cheaper method for sealing thermoplastic containers, without using costly conventional screw-on sealing caps.
This invention further offers a unique method for making a container without joints that can be easily tampered with.
This invention also relates to spray pumps in that it offers a novel and less costly method for obtaining a liquid jet stream discharge.
2. Description of the Prior Art:
U.S. Pat. No. 3,610,477 (Herzig) discloses a squeeze bottle having an automatic closure. The automatic closure is the result of forming the end of the container, as by heat sealing. Different embodiments are disclosed, such as reinforcing ribs for the closure, a clip which fits over the container outlet, and nested curves formed in panels at the outlet. Material is expelled from the container by squeezing the container to open the lips.
U.S. Pat. No. 3,777,949 (Chiquiaria-Arias) discloses a disposable container having a tab sealing the discharge opening and a cap covering the discharge opening and the tab. The cap is used to twist off the tab so that there is no contamination by contact with the hands in removing the tab.
U.S. Pat. No. 4,252,257 (Herzig) discloses a container having a pinch-off fold at an outlet. Discharge of the container requires the use of pressure being applied at its different areas. When the pressure is released, the outlet closes automatically due to internal pressure of the material in the container. The discharge of material requires two hands, with the fingers of one hand applying pressure at a specific area to cause the discharge opening to open and then pressure on the container for discharging the contents. Liquids only may be discharged from the apparatus since the internal pressure of the liquids is required to maintain the seal.
U.S. Pat. No. 4,553,686 (Dougherty) discloses a drop dispenser apparatus with a patent configuration of seal elements or valves at the discharge portion of the apparatus. As with the Herzig U.S. Pat. No. 4,252,257, the apparatus is designed only for discharging liquids, and the apparatus is specifically designed for discharging drops of a liquid. The container is deformable, and pressure is applied to the container to discharge the liquid drops.
It is acknowledged that seal or shipping tabs are presently used, such as depicted in U.S. Pat. No. 3,777,949 (Chiquiaria-Arias). Most, however, seal off a container outlet, which upon removal of the seal tab, exposes a discharge opening that normally cannot be resealed, unless provided with a separate cap. Whereas, the apparatus herein offers a seal tab, which when removed exposes the closed outlet lips of the self-closing valve which can be digitally opened or closed as desired. It is further acknowledged that other types of seal tab such as depicted, but not claimed, in Herzig's U.S. Pat. Nos. 3,610,477 and 4,252,257 for automatic closures provides a removable cover which can not be considered gas tight such as claimed in the application herein. Furthermore, the seal tab claimed herein is an integral part of the self-closing valve body which is formed simultaneously during the thermoforming of the self-closing valve. No additional cover, cap or separate operation is needed for making the seal. The most novel part of this lip seal tab is that it can be provided with a built-in lip seal clip housing which is also an integral part of the self-closing valve. To further enhance the tamper-proofing merits of this seal tab, the Company Logo can be imbedded across the scored portion, where the valve discharge lips and the lip seal tab portion are joined, thus making tampering at this joint more difficult to reseal and match the halved company logo.
It is also acknowledged that other types of automatic closures for handling liquids have been patented, such as Hergiz's U.S. Pat. Nos. 3,610,477 and 4,252,257, which require they be made part of a flexible thin film tubular shaped container capable of being squeezed in order to dispense the liquid; whereas the self-closing valve described herein can be fastened to any container, whether rigid, flexible, or otherwise, since the valve itself is structurally designed to allow it to be digitally squeezed for dispensing product be it liquid, paste or solids such as pills, capsules, etc.
Most plastic bottles or containers depend on a seal to keep the contents from escaping, yet permit easy opening and resealing.
A variety of closures are presently being used to facilitate the sealing and opening, such as flip-top caps with built-in or swing-out pouring spouts, snap caps, twist and push-down types, which normally require a threaded joint for fastening to the container which requires extra wall thickness at the bottle neck and shoulder for making the threaded joint tight and resistant to top load stress, shear and deformation during the capping operation. Often additional gaskets or glued-on tamper evident aluminum or plastic liners are required to make the seal tight.
The dairy and fruit juice industries have developed packaging concepts employing plastic tear-off caps when large plastic containers (one or half gallon sizes) are used. For smaller sizes, having shorter shelf life, the famous pre-waxed or plastic coated, flat-topped gable roofed cardboard container is used, where the user has to tear part of the top off and bend part of the gable out to form the discharge spout. The usage of an all plastic self-closing valve and container eliminates the problems encountered with opening the cardboard spout, providing a more positive closure and leak proof container. For the larger half and one gallon plastic containers, the self-closing valve can be incorporated into the container's lifting handle and made into a combination lifting, pouring, discharge spout. Naturally this feature can be used for other products besides milk and juices.
Metal cans are often used for soft drinks and beer and the like, which when unsealed have no provision for preventing the decarbonation and decomposition of the contents whereas plastic cans with a self closing valve, with lip seal tab having a built-in seal clip housing could be used. This same concept could be used by the canning industry, provided a suitable vapor barrier can be developed for foods that require longer shelf life.